Portable electric saw and switch mounting means therefor



April 12, 1966 M. 1. SHEPS ETAL 3,245,439

PORTABLE ELECTRIC SAW AND SWITCH MOUNTING MEANS THEREFOR Filed June 5, 1964 2 Sheets-Sheet l INVENTORS MARTIN I. SHEPS JACOBUS J. BECKERING BY z ATTORNEY April 12, 1966 M. 1. SHEPS ETAL PORTABLE ELECTRIC SAW AND SWITCH MOUNTING MEANS THEREFOR 2 Sheets-Sheet 2 Filed June 5, 1964 sabl IN VENTORS MARTIN l. SHEPS JACOBUS J. BECKERING BY /mf%?*ny- ATTORNEY United States Patent 3,245,439 PORTABLE ELECTRIC SAV AND SWITCH MOUNTING MEANS THEREFOR Martin I. S heps, Baltimore, and Jacobus J. Beekering,

Bel Air, Md., assignors to The Black and Decker Manufactoring Company, Towson, Md., a corporation of Maryland A V I Filed June 3, 1964, Ser. No. 372,197 9 Claims. (GI.- 143-43) The present invention relates to a portable electric saw, and more particularly, to an improved saw structure which facilitates an economical construction of the unit, yet provides a rugged and reliable tool for superior performance over extended periods of time.

It is an object of the present invention to provide a portable electric saw utilizing a split housing, generally referred to in the art as a clam shell design, and one in which not only the motor housing, but also the upper switch handle and the blade guard, are cast integrally with the mating halves of the split housing.

It is another object of the present invention to provide an improved switch mounting means for a tool, one which comprises an entrapment of the switch body between the mating handle portions of the split housing.

In accordance with the teachings of the present invention, a preferred embodiment of a portable electric saw is herein illustrated and described, which comprises a split housing including a pair of complementary mating halves, one of which constitutes the first half, and the other the second half. The first half comprises a minor portion functioning as a' cover, while the second half comprises the major portion within which the various electrical and mechanical components are readily assembled together. Means are provided for detachably securi-ng the mating halves together along a' common plane which, preferably, is angularly skewed by an acute angle with respect to a true vertical plane and in the direction in which the saw is guided into the work. Each of the mating halves of the split housing has respective portions, complementary to those in the other half, forming a casing for the electric motor, an upper guard for the saw blade, and an'upper switch handle. The respective upper switch handle portion of the first half extends substantial ly [transverse to the skewed common plane and forms a hand grip to manually guide and control the saw.

within .the respective upper switch handle portion of the second half and projects therefrom, substantially transverse to the common plane, into the respective upper switch handle portion of the first half. Preferably,- the switch body is trapped between the complementary upper switch handle portions of the mating halves of the split housing when the mating halves are secured together.

The respective upper switch handle portion of the first half has a bottom wall with a window formed therein; and the switch has a manually manipulatable trigger carried by the switch body and projecting therefrom through'th'e window for engagement by the operator, the trigger being mounted on the switch body for sliding movement, preferably, along an axis which is substantially parallel to the skewed common plane. A strut is cast integrally between the bottom wall of the upper switch handle portion of the first mating half and the respective motor casing portion thereof, rearwardly of the window, and serves the dual function of a structural support and a guard for the trigger. Moreover, the upper switch handle portion of the first mating half has a forward wall, depending from its bottom wall, with an access opening formed therein to communicate with the window, thereby providing the necessary clearance to allow for the pas- A electric switch is provided which has a body portion seated I Patented Apr. 12, 1966 sage of the trigger into the upper switch handle portion of the first half when the mating halves of the split housing are brought together; and means are then provided for covering the access opening forwardly of the trigger in the subsequent assembly of the unit. I I

These and other objects of the present invention will become apparent from a reading of the following specification, taken in conjunction with the enclosed drawings,inwhich: I I II I FIGURE 1 is a side elevation of a portable electric saw embodying the teaching of the present invention;

FIGURE 2 is an elevation of the saw of FIGURE l as viewed from the opposite side; I I I I I I I I FIGURE 3 is a top plan View of the saw, with part of the casing being broken away to illustrate the electric motor; I I I I I FIGURE 4 is an enlarged fragmentary portion of FIG- URE 2 with part of the casing being broken away to illustrate the electric switch and the improved mounting meanstherefor; I I I I I I FIGURE 5 is a stepped transverse section view taken along the lines 55 of FIGURE 4; FIGURE 6 is a section view taken along the lines 6-6 of FIGURE 4, the broken lines denoting the manner in which the flanged base of th e switch is seated in the major half of the split housing; I I I FIGURE 7 is a longitudinal section'of the overalls aw, the view being taken along the lines 7'-7 of FIGURE 2, and looking into the major half of the split housing;

FIGURE 8 is" an exploded perspective showing the respective upper control handle portion of the major half together with the electric switch, the latter being turned away from the viewer to illustrate its flanged base and the respective notched lands formed therein; and V FIGURE 9 is an exploded perspective showing the switch seated withirithe respective upper control handle portion of the major half of the split housing with the minor half of the split housing in a position to trap the switch in place when the mating halves are secured together. With particular reference to FIGURES 1 and 2, the portable electric saw 10 comprises a split housing, which preferably is die cast from aluminum and is commonly referred to in the art as a; clam shell housing; and the split housing includes a pair of complementary mating halves I1 and 12,- one of which, 11, may be designated as the first half and preferably comprises the minor half or cover portion, and the other of which, 12, may be designated as the second half and preferably comprises the major half within which the various electrical and mechanical components of the saw may be assembled. Naturally, it willbo appreciated by those skilled in the art that the function of the castings 11 and 12 may be reversed; the components may be assembled, if desired, in'what n'ow'constitutes the minor half, and the major half may then serve as a cover. The mating halves 11 and 12 are detachably secured together along a common plane AB, see FIGURE 4, which is commonly referred to in the art as the parting line between the castings; and preferably, the com-' mon plane is angularly skewed by an acute angle, def: noted as at a in FIGURE 1, with respect to a true vertical plane and away from the direction in which the saw 10 is guided me the work. Each of the mating halves 11 and 12 of thesplit housing has respective por Moreover, the saw further comprises a substantially flat shoe plate 18 by nieans'of which the unit may be supported upon the top surface of a workpiece; a rip fence 19, see FIGURE 3 again, removably secured to the shoe; a lower guard for covering the portion of the blade which projects below the shoe, the lower guard 20 being spring-loaded and pivotably mounted and being adapted to telescope within the upper guard upon engagement with the workpiece in the usual manner; a knob 21 carried by the lower guard to facilitate its optional manual retraction; a discharge chute 22 formed in the upper guard for egress of the saw chips and particles; a conventional depth adjustment means comprising a pivot point 23, a depth control member 24 with an arcuate slot 25, and a wing nut 26; and a conventional bevel adjustment means comprising a bevel quadrant 27 and a wing nut 28 for selectively tilting the housing with respect to the shoe plate to facilitate the making of a bevel cut.

Preferably, the various electrical and mechanical components of the unit are assembled together in the major half 12, see FIGURE 7, while the minor half 11 serves as a cover; and the components are trapped in place when the mating halves are secured together. In the preferred embodiment, the mating half 12 is the major half; however, the procedure could be reversed as previously noted. With this in mind, the saw further includes the electric motor, which comprises an armature 29 and field 30. The field 30 is trapped between the mating halves of the split housing with a flat spring 31 being disposed against the field and the inner Wall of one casting as shown in FIGURE 3. The armature has a shaft 32 which is journaled in bushings 33 and 34, and the armature carries a commutator 35 which engages electrical brushes 36. The brushes 36 are mounted in respective brush holders 37, and the brushes are resiliently biased by respective coil springs 38 seated within the holders. The forward portion of the armature shaft carries a fan 39 for drawing cooling air through a plurality of air inlet openings 40 formed in the rear of the motor casing, see FIGURE 2, for discharge through a variety of air exit openings, one of which is denoted at 41 in FIG URE 7. A pinion 42 is formed on the end of the armature shaft for engagement with a gear 43. The gear is mounted on a spindle 44 which is journaled in bushings 45 and 46; and the saw blade 16 is secured to the spindle by means of a clamping screw 47. Preferably, the bushings (or equivalent bearings) 33, 34, 45, and 46, as well as the brush holders 37 and field 30, are trapped between the mating halves 11 and 12 of the split housing as these mating halves are secured together.

The upper switch handle 17, see FIGURES 1 and 2 again, is split along the skewed common plane or parting line AB and has respective portions included in the mating halves of the split housing. The respective upper switch handle portion of the first half 11 extends substantially transverse to the skewed common plane and forms a hand grip 48 to manually guide and control the saw. The significance of having the common plane skewed is that only two castings (members 11 and 12) are necessary to obtain not only the motor casing and gear housing, but more importantly, the upper switch handle 17 and the upper guard 15 for the saw blade, yet this is fully consonant with having the desired rake on the hand grip 48, so that it is comfortable and convenient for the operator to use the saw; and thus a resultant economy in manufacturing is obtained together with the desired functional quality.

The present invention resides, moreover, in an 'improved switch mounting means for the tool, and this means may be appreciated more readily by referring again to FIGURE 4 and also to the remaining FIGURES 5, 6, 8 and 9. An electric switch 49 is provided which has a body portion 50 with a flanged base 51. The base .51 is preferably rectangular in plan outline and has a lower protrusion 52 at each corner. Each of the protrusions 52 extends below the under surface of the switch base 4 and has a notch 53 formed therein. A corresponding plurality of spaced lands 54 is formed in the respective upper switch handle portion of the major half 12, see FIGURE 8; and each land 54 has a recessed ledge 55 formed therein to receive a respective notch 53 of the switch base, thereby seating the switch body in the respective upper switch handle portion of the major half 12 as shown more clearly in FIGURE 9. A pair of ribs 56, see FIGURE 5, is formed within the respective upper switch handle portion (comprising the hand grip 48) of the minor half 11; and the ribs are disposed on the re spective sides of the switch body and engage the upper surface of the flanged base 51 of the switch body, see FIGURE 5, to thereby trap the base of the switch between the mating halves 11 and 12 of the split housing.

The respective upper switch handle portion 48 of the minor half 11 has a bottom wall 57 with a window 58 formed therein, and the switch has a manually-manipulatable trigger 59 carried by the switch body and projecting therefrom through the window 58 for engagement by the operator. Preferably, but not necessarily, the trigger 59 is mounted on the switch body for sliding movement along an axis which is substantially parallel to the skewed common plane AB.

Moreover, the respective upper switch handle portion 48 of the minor half 11 has a forward wall 60, see FIGURE 4 again, which depends from the bottom wall 57; and the forward wall 60 has an access opening 61 formed therein for the trigger 59, the access opening 61 communicating with the window 58 and allowing the trigger 59 to project into the hand grip portion 48 of the housing as the mating halves 11 and 12 of the split housing are secured together. In the subsequent assem-- bly of the tool, however, the access opening 61 is prefer ably closed (forwardly of the trigger) by a plastic cover' 62 or other suitable closure means. A strut 63, moreover, is integrally cast between the bottom wall 57 of the hand grip portion 48 of the upper switch handle 17 and the respective motor casing portion 13 of the minor mating half 11. The strut 63 is positioned rearwardly of the window 58 and serves the dual function of a structural support and a guard for the trigger.

The saw 10 is energized by means of the electrical cord 64 and plug 65,-see FIGURE 7, and the cord 64 is connected to the motor and switch by a plurality of wires (not denoted separately). The mating halves 11 and 12 of the split housing are secured together by a plurality of screws 66, see FIGURE 4, which are received in corresponding tapped recesses 67 formed in the major half 12.

Obviously, many modifications may be made without departing from the basic spirit of the present invention; and accordingly, within the scope of the appended claims, the invention may be practiced other than has been specifically described herein.

We claim:

1. In a portable electric saw, the combination which comprises:

(a) a split housing including a pair of complementary mating halves, one of which constitutes the first half, and the other the second half;

(b) means to detachably secure said mating halves together along a common plane;

(0) said plane being angularly skewed by an acute angle with respect to a true vertical plane away from the direction in which the saw is guided into the work;

(d) each of said mating halves having respective portions, complementary to those in the other half, forming:

(1) a casing for an electric motor; (2) an upper guard for a saw blade; and (3) an upper switch handle; (e) said respective upper switch handle porfion of said first half extending substantially transverse to said skewed common plane and forming a hand grip to manually guide and control the saw;

(f) an electric switch having a body portion seated within said respective upper switch handle portion of said second half and projecting therefrom, substantially transverse to said skewed common plane, into said respective upper switch handle portion of said first half;

(g) means to trap said switch body between said complementary upper switch handle portions of said mating halves of said split housing;

(h) said respective upper switch handle portion of said first half having a bottom wall with a window formed therein; and

(i) said switch further having a manually-manipulatable trigger carried by said switch body and projecting therefrom through said window.

2. The combination of claim 1, wherein:

(a) said trigger is mounted on said switch body for sliding movement along an axis which is substantially parallel to said skewed common plane.

3. The combination of claim 1, wherein:

(a) a strut is integrally cast between said bottom wall of said upper switch handle portion of said first half and said respective motor casing portion thereof;

7 (b) said strut being positioned rearwardly of said window, whereby said strut serves the dual function of a structural support and a guard for said trigger.

4. The combination of claim 1, wherein:

(a) said respective upper switch handle portion of said first half has a forward wall depending from said bottom wall thereof;

(b) said forward wall having an access opening formed therein for said trigger, said access opening communicating with said window; and

(c) means covering said access opening forwardly of said triggger.

5. The combination of claim 1, wherein said means to trap said switch body comprises:

(a) a flanged base formed on said switch body;

(b) said flanged base having a lower protrusion at each corner thereof;

(0) said protrusions each extending below the under surface of said switch base and each being formed with a notch therein;

((1) said respective upper switch handle portion of said second half having a corresponding plurality of spaced lands, one for each of said protrusions;

(e) each of said lands having a ledge to receive a respective one of said notches, thereby seating said switch body in said respective upper handle portion of said second half; and

(f) a pair of ribs formed within said respective upper switch handle portion of said first half, one on each side of said flanged base and engaging the upper surface of said base, thereby trapping said base between the mating halves of the split housing.

6. In a portable electric saw, the combination which comprises:

(e) said'respective upper switch handle portion of one of said halves extending substantially transverse to said common plane and forming a hand grip to manually guide and control the saw;

(f) said respective upper switch handle portion of said one half having a bottom wall with a window formed therein;

(g) an electric switch having a body portion housed substantially within said upper switch handle portion of said one half;

(h) said switch further having a movable trigger carried by said switch body and depending therefrom through said window; and

-(i) a strut between said bottom wall of said respective upper switch handle portion of said one half and said respective motor casing portion thereof, said strut being rearwardly of said window.

7. In a portable electric saw, the combination which comprises:

(a) a pair of mating handle housing portions secured together along a common plane and forming an upper control handle for the saw;

(b) one of said handle housing portions extending substantially transverse to said common plane and forming a hand grip to manually guide and control the saw;

(c) an electric switch having a body portion seated within the other of said handle housing portions, extending laterally therefrom substantially transverse to said common plane, and being received within said one handle housing portion;

(-d) said one handle housing portion having a bottom wall with a window formed therein;

(e) said one handle housing portion further having a forward wall depending from said bottom wall; (f) said forward wall having an access opening formed therein for said trigger, said access opening communicating with said window;

(g) said switch further having a movable trigger carried by said switch body and depending therefrom through said window; and

(h) means covering said access opening forwardly of said trigger.

8. In a portable electric saw, the combination which comprises:

(a) a pair of mating handle housing portions comprising a first portion and a second portion secured together along a common plane and forming an upper control handle for the saw;

(b) an electric switch having a body portion seated within said second handle housing portion, extending therefrom across said common plane, and being received within said first handle housing portion;

(c) said first handle housing portion having a bottom wall with a window formed therein;

((1) said first handle housing portion further having a forward wall depending from said bottom wall, said forward .wall having an access opening formed [therein communicating with said window;

(e) said switch further having a movable trigger carried by said switch body and depending therefrom through said window;

(if) means covering said access opening forwardly of said trigger; and

(g) a strut depending from said bottom wall of said first handle housing portion rearwardly of said window.

9. Switch mounting means for a portable electric tool,

comprising (a) a handle split transversely of its longitudinal axis and comprising a pair of mating portions secured together along a common plane;

(b) an electric switch having a body portion seated within one of said mating portions and extending therefrom across said common plane and into the other of said mating portions;

(0) means to trap said switch body between said mating portions of said handle;

(d) said other mating portion having a window formed therein and further having an access opening formed transversely therein adjacent to said Window and communicating therewith;

(e) said switch further having a movable trigger carried by said switch body and projecting therefrom through said window; and

(f) means covering said access opening forwardly of said trigger.

No references cited.

WILLIAM W. DYER, JR., Primary Examiner.

W. D. BRAY, Assistant Examiner. 

1. IN A PORTABLE ELECTRIC SAW, THE COMBINATION WHICH COMPRISES: (A) A SPLIT HOUSING INCLUDING A PAIR OF COMPLEMENTARY MATING HALVES, ONE OF WHICH CONSTITUTES THE FIRST HALF, AND THE OTHER THE SECOND HALF; (B) MEANS TO DETACHABLY SECURE SAID MATING HALVES TOGETHER ALONG A COMMON PLANE; (C) SAID PLANE BEING ANGULARLY SKEWED BY AN ACUTE ANGLE WITH RESPECT TO A TRUE VERTICAL PLANE AWAY FROM THE DIRECTION IN WHICH THE SAW IS GUIDED INTO THE WORK; (D) EACH OF SAID MATING HALVES HAVING RESPECTIVE PORTIONS, COMPLEMENTARY TO THOSE IN THE OTHER HALF, FORMING: (1) A CASING FOR AN ELECTRIC MOTOR; (2) AN UPPER SWITCH FOR A SAW BLADE; AND (3) AN UPPER SWITCH HANDLE; (E) SAID RESPECTIVE UPPER SWITCH HANDLE PORTION OF SAID FIRST HALF EXTENDING SUBSTANTIALLY TRANSVERSE TO SAID SKEWED COMMON PLANE AND FORMING A HAND GRIP TO MANUALLY GUIDE AND CONTROL THE SAW; 